Cinematographic apparatus

ABSTRACT

The takeup reel of a cimenatographic apparatus is rotated by the claw pull-down which pivots one arm of a two-armed lever by way of a torsion spring. The other arm of the lever carries two pivotable spring-biased pawls which cooperate with a toothed wheel on the takeup reel in such a way that one of the pawls rotates the wheel in a direction to enable the takeup reel to collect the film when the pull-down pivots the lever in a clockwise direction and that the other pawl rotates the wheel in the same direction as the one pawl when the pull-down pivots the lever in a counterclockwise direction.

United States Patent 1151 3,706,427 Theer 1 I 1 Dec. 19, 1972 [54]CINEMATOGRAPHIC APPARATUS 3,570,783 3/1972 Winkler ..242/205 [72]Inventor: Anton Theer, Munich, Germany Primary Examiner-Leonard D.Christian [73] Assignee: Agfa Gevaert A.G., Munich, Ger- Amey Michae] S.Striker many [22] 7 Filed: Aug. 23, 1971 [57] ABSTRACT [2]] Appl. No.:173,771 The takeup reel of a cimenatographic apparatus is rotated by theclaw pull-down which pivots one arm of a two-armed lever by way of atorsion spring. The [30] Foreign Apphcauon Pnonty Data other arm of thelever carries two pivotable spring- Aug. 27, 1970 Germany P 7O 31 984.5biased pawls which cooperate with a toothed wheel on the takeup reel insuch a way that one of the pawls [52] [1.5. CI ..242/205, 352/191rotates the wheel in a direction to enable the takeup [51] llit. CI...Bllb 15/32, G03b 1/04 reel to collect the film when the pulhdownpivots the [-8] new of Search "242/205'2); 352/l87"l96 lever in aclockwise direction and that the other pawl rotates the wheel in thesame direction as the one [56] References cued pawl when the pull-downpivots the lever in a counter- UNITED STATES PATENTS clockwlsedlriclloni 3,061,l60 /1962 Elsas ..226/58 Claims, 1 Drawing FigureCROSS-REFERENCE TO RELATED INVENTION The cinematographic apparatus ofthis invention constitutes an improvement over and a further developmentof the apparatus which is disclosed in U.S. Pat. No. 3,570,783, grantedMar. 16, 1971 to Friedrich Winkler et al and owned by the assignee ofthe present application.

BACKGROUND or THE INVENTION The present invention relates tocinematographic apparatus in general, and more particularly toimprovements in the mechanisms which are used in motion picture camerasor motion picture projectors to drive a film collecting member, such asa takeup spool or reel. Still more particularly, the invention relatesto improvements in drive mechanisms which employ ratchet and pawl meansto intermittently rotate the takeup or film collecting member in amotion picture camera or projector.

The aforementioned U.S. Pat. No. 3,570,783 to Winkler et al discloses acinematographic apparatus wherein the takeup reel can be rotated by afirst ratchet wheel or gear which meshes with a second gear. A leverwhich is pivotable in the body of the cinematographic apparatus isoscillated by the claw pull-down or feeder of the film transportingdevice and carries two pawls each of which cooperates with one of thegears in such a way that the first gear is rotated in a single directionirrespective of whether it receives motion directly from one of thepawls or whether the other pawl rotates the second gear. An advantage ofthe just described cinematographic apparatus is that-the mechanism whichrotates the takeup reel is simple, rugged and has a minimal number ofparts. Also, the customary friction SUMMARY OF THE INVENTION An objectof the invention is to provide a cinematographic apparatus with a noveland improved mechanism which serves to rotate the film collecting memberand is simpler, more compact and at least as reliable and versatile aspresently known mechanisms including that which is disclosed in theaforediscussed U.S. Pat. No. 3,570,783.

Another object of the invention is to provide a drive mechanism whichcan be used with advantage to rotate the film collecting member of acinematographic apparatus and comprises a minimal number ofprecisionfinished parts but is still capable of insuring automaticwinding of exposed or projected film frames at the rate which isdetermined by the rate of film transport by the customary claw pull-downor an analogous film feeding device.

The invention is embodied in a cinematographic apparatus which comprisesa rotary spool, reel or an analogous film collecting member, a toothedwheel or gear which is arranged to transmit torque to the filmcollecting member (such gear may constitute a ratchet wheel which isrigidly secured to a takeup reel), a film transporting mechanismincluding a driving member which is arranged to perform first recurrentmovements (such driving member may form an integral or detachable partof a claw pull-down and may be designed and mounted to perform recurrentoscillating, reciprocatory or other movements), and novel motiontransmitting means for rotating the gear in a single direction inresponse to recurrent movements of the driving member.

The motion transmitting means comprises a slide, a lever or an analogouscarrier which normally receives motion from the driving member (eitherdirectly or by way of a torsion spring or analogous biasing means) andis constructed and mounted to thereby perform second recurrent movementsincluding alternating movements in first and second directions, and apair of pawls which are preferably pivotably mounted on the carrier andare preferably biased against the teeth of the gear by helical springsor other suitable resilient means. One of the pawls serves to rotate thegear in the single direction in response to each movement of the carrierin the first direction, and-the other pawl serves to rotate the gear inthe single direction in response to each movement of the carrier in thesecond direction.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims.

The improved cinematographic apparatus itself, however, both as to itsconstruction and its mode of operation, together with additionalfeatures and advantages thereof, will be best understood upon perusal ofthe following detailed description of certain specific embodiments withreference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is a fragmentarydiagrammatic partly sectional view of a motion picture camera whichembodies the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawing illustrates aportion of a motion picture camera for use with 8-millimeter film. Thecamera comprises a housing or body 1 wherein a strip of film F istransported from a supply reel (not shown) or an analogous source ofunexposed film to a film collecting member here shown as a takeup reelR. The film transporting mechanism comprises a feeder in the form of aclaw pull-down 15 having a claw 15a which can enter the perforations Pof the film F and advances the film forwardly by the length of a framewhile the shutter (not shown) seals the light-admitting aperture. Thepull-down l5 performs recurrent movements under the action of aneccentric 16 which is rigid with a gear 17 mounted on a shaft 18. Thegear 17 meshes with a gear 19 which is coaxial with a gear 20. the gears19, 20 are mounted on a shaft 21 and the gear 20 meshes with a gear 22on the output shaft 24 of an electric motor 23.

When the motor 23 is on, the gear train 22, 20, l9, 17 causes theeccentric 16 to impart to the claw pull-down the aforementionedrecurrent movements whereby the claw 15a transports the film F stepwise,always by the length of a frame.

The pull-down 15 is rigidly or separably connected with or made integralwith a driving member or projection 2 which moves in and counter to thedirection indicated by the arrow A when the motor 23 is on to operatethe pull-down 15. The driving member 2 performs recurrent reciprocatoryor oscillatory movements which are transmitted to the takeup reel R byway ofa motion transmitting mechanism which is constructed and assembledin accordance with the present invention. The motion transmittingmechanism comprises basically a carrier in the form of a two-armed lever7 and two pawls 8, 9 which are pivotably mounted on pins 8a, 9a providedon the arm 7a of the carrier .or lever 7. The latter is pivotable backand forth about the axis of a shaft 6 which is fixedly mounted in thehousing 1 of the motion picture camera. The shaft for the takeup reel Ris shown at 3. This shaft defines an axis of rotation for a toothedmember here shown as a ratchet wheel or gear 4 having an annulus ofteeth 4a" which can be engaged by the pallets of the pawls 8, 9 inresponse to recurrent back-and-forth pivotal movements of the lever 7about the axis of the shaft 6. The wheel or gear 4 is directly orindirectly connected with the takeup reel R so that it can transmittorque thereto in order to rotate the reel R in a direction to collectthe film F. I

The motion transmitting mechanism between the wheel or gear 4 for thetakeup reel R and the driving member 2 of the film transportingmechanism further comprises a first biasing means here shown as atorsion spring 12 one leg of which bears against the driving member 2and the other leg of which bears against a stop 7b on the arm 7a of thelever 7. The median portion of the torsion spring 12 is convolutedaround the shaft 6 and this spring is mounted in prestressed conditionso that its legs normally bear against the aforementioned stop 7b on thearm 70 and against a second stop 7e on the arm 7d of the lever 7. Asecond biasing means 13, also shown in the form of a torsion spring, isconvoluted around a fixed shaft 13a and has two legs one of which bearsagainst a stationary stop 1a in the housing 1 and the other of whichbears against a pin-shaped stop 7c on the arm 7a of the lever 7. Thespring 13 tends to pivot the lever 7 in a clockwise direction, as viewedin the drawing. The arm 7a of the lever 7 further carries two resilientelements in the form of helical springs 10, 11 which respectively biasthe pallets of the pawls 8 and 9 against the adjacent teeth 4a of thewheel 4. I

The wheel 4 can drive a footage counter FC whose construction is'preferably identical with or analogous to that of the footage counterwhich is disclosed in US. PatNo. 3,578,856 granted May 18', 1971 to KurtThate et al and owned by the assignee of the present application. The.footage counter FC has a gear or wheelS which is in mesh with andreceives torque from the wheel 4. g s

The arm 7a of the lever 7 includes a substantially U- shaped orsemicircular portion which carries the stop 70 and the pawls8, 9. Itwill be noted that the point (stop 7c) where the spring l3'bears againstthe arm 7a is remote from the points (stops 7b, 7e) where the lever 7 isengaged by the spring 12. The pawls 8, 9 are disposed substantiallydiametrically opposite each other with reference to the axis of theshaft 3, i.e., with reference to the axis of rotation of the wheel 4.

THE OPERATION When the motor 23 is on so that the gear train 22,20, l9,17 rotates the eccentric 16, the latter causes the claw pull-down 15 toperform recurrent movements and to thereby move the driving member 2 inand counter to the direction indicated by the arrow A. When the drivingmember 2 moves in the direction which is indicated by the arrow A, thespring 13 pivots the lever 7 in aclockwise direction about the axis ofthe shaft 6 so that the spring 12 continues to remain in en gagementwith the driving member 2. Such clockwise pivotal movement of the lever7 causes the pawl 9 to engage the adjacent tooth 4a and to rotate thewheel 4 and the takeup reel R in a counterclockwise direction, as viewedin the drawing. At the same time, the pallet of the pawl 8 rides orratchets over the adjacent teeth 4a. When the driving member 2 thereuponmoves counter to the direction indicated by the arrow A, it entrains theadjacent leg of the spring 12 and causes the lever 7 to pivot in acounterclockwise direction against the opposition of the spring 13. Thepallet of the pawl 9 rides over the adjacent teeth 4a but the pallet ofthe pawl 8 engages one of the teeth 4a and rotates the wheel 4 and hencethe takeup reel R in a counterclockwise direction, i.e., in the samedirection in which the wheel 4 was rotated by the pawl 9 while thedriving member 2 was moving in the direction indicatedby the arrow A.The springs 10, 11 preferably insure that the pallets of the pawls 8, 9remain in engagement with the teeth 4a at all times; however, the spring10 allows the pallet of the pawl 8 to ride over the teeth 4a when the.lever 7 is caused to pivot in a clockwise direction and the spring 11allows the pallet of the pawl 9 to ride over the teeth 4a when the lever7 is caused to pivot in a counterclockwise direction. The spring 13exhibits the tendency to move the arm 7a of the lever 7 against thewheel 4. v

If the wheel 4 cannot rotate any further (for example, because theentire film F is already convoluted on the reel R) but the motor 23continues to operate'the claw pull-down 15, the spring 13 is unable topivot the lever 7 clockwise while the driving member 2 moves in thedirection indicated by the arrow A. Thus, the inability of the wheel 4to rotate counterclockwise does not affect the operation of the drivingmember 2 and pull-down 15. The driving member 2 then simply moves awayfrom and back into abutment with the adjacent leg of the spring 12. Ifthe wheel 4 is arrested while the driving member 2 moves counter to thedirection indicated by the arrow A, the driving member simply stressesthe spring 12 by moving the adjacent leg of this spring away from thestop 7e. The lever 7 77 remains at a standstill.

An important advantage of the improved motion transmitting mechanismbetween the driving member 2 and the wheel 4 for the takeup reel R isthat the pawls 8, 9 cooperate with a single toothed member 4. This isincontrast to the construction of the mechanism which is shown in theaforementioned US. Pat. No. 3,570,783 and wherein each of the two pawlscooperates with a discrete toothed member. It is clear that theinvention can be incorporated with equal advantage in other types ofmotion picture cameras and/or in motion picture projectors.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of my contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

Iclaim:

1. In a cinematographic apparatus, a combination comprising a rotaryfilm collecting member; a toothed wheel arranged to transmit torque tosaid film collecting member; a film transporting mechanism including adriving member arranged to perform first recurrent movements; and motiontransmitting means for rotating said wheel in a single direction inresponse to recurrent movements of said driving member, said motiontransmitting means comprising a carrier normally receiving motion fromsaid driving member and arranged to thereby perform second recurrentmovements including alternating movements in first and seconddirections, and a pair of pawls mounted on said carrier, one of saidpawls being arranged to rotate said wheel in said single direction inresponse to each move ment of said carrier in said first direction andthe other of said pawls being arranged to rotate said wheel in saidsingle direction in response to each movement of said carrier in saidsecond direction.

2. A combination as defined in claim 1, wherein said carrier is a leverwhich is pivotable by said driving member back and forth about apredetermined axis to thereby perform said alternating first and secondmovement.

3. A combination as defined in claim 1, wherein each of said pawl ispivotably mounted on said carrier and further comprising resilient meansfor biasing said pawls against the teeth of said wheel and forpermitting said other pawl to ride over such teeth when said wheel isrotated by said one pawl, and vice versa.

4. A combination as defined in claim ll, wherein said film transportingmechanism comprises a claw pulldown and said driving member receivesmotion from said claw pull-down.

5. A combination as defined in claim 4, wherein said driving member isrigid with said claw pull-down. I

6. A combination as-defined in claim 1, wherein said wheel is rigid withsaid film collecting member.

7. A combination as defined in claim 1, wherein said pawls are disposedsubstantially diametrically opposite each other with reference to theaxis of said wheel.

8. A combination as defined in claim 7, wherein said carrier is a leverwhich is pivotable about a predetermined axis and comprises a first armand a second arm, said first arm receiving motion from said drivingmember and said pawls being mounted on said second arm.

9. A combination as defined in cla1m 8, wherein the second arm of saidlever is substantially U-shaped.

10. A combination as defined in claim 1, wherein said motiontransmitting means further comprises biasing means interposed betweensaid driving member and said carrier to normally move said carrier inresponse to movement of said driving member.

11. A combination as defined in claim 10, wherein said carrier is alever which is pivotable in said first and second directions about apredetermined axis, said lever having a first arm which receives motionfrom said driving member by way of said biasing means and a second armwhich supports said pawls.

12. A combination as defined in claim 11, wherein said second arm ofsaid lever is substantially U-shaped and said pawls are mounted on saidsecond arm substantially diametrically opposite each other withreference to the axis of said wheel.

13. A combination as defined in claim 12, further comprising secondbiasing means permanently tending to pivot said lever in one of saidfirst and second directions.

14. A combination as defined in claim 1, wherein said carrier is a leverhaving an arm which supports said pawls, said motion transmitting meansfurther comprising first biasing means engaging said arm and arranged tobias said lever in one of said first and second directions and secondbiasing means arranged to transmit motion from said driving member to aportion of said lever which is remote from the point of engagementbetween said arm and said first biasing means.

15. A combination as defined in claim 14, wherein at least one of saidbiasing means is a torsion spring.

1. In a cinematographic apparatus, a combination comprising a rotaryfilm collecting member; a toothed wheel arranged to transmit torque tosaid film collecting member; a film transporting mechanism including adriving member arranged to perform first recurrent movements; and motiontransmitting means for rotating said wheel in a single direction inresponse to recurrent movements of said driving member, said motiontransmitting means comprising a carrier normally receiving motion fromsaid driving member and arranged to thereby perform second recurrentmovements including alternating movements in first and seconddirections, and a pair of pawls mounted on said carrier, one of saidpawls being arranged to rotate said wheel in said single direction inresponse to each movement of said carrier in said first direction andthe other of said pawls being arranged to rotate said wheel in saidsingle direction in response to each movement of said carrier in saidsEcond direction.
 2. A combination as defined in claim 1, wherein saidcarrier is a lever which is pivotable by said driving member back andforth about a predetermined axis to thereby perform said alternatingfirst and second movement.
 3. A combination as defined in claim 1,wherein each of said pawl is pivotably mounted on said carrier andfurther comprising resilient means for biasing said pawls against theteeth of said wheel and for permitting said other pawl to ride over suchteeth when said wheel is rotated by said one pawl, and vice versa.
 4. Acombination as defined in claim 1, wherein said film transportingmechanism comprises a claw pull-down and said driving member receivesmotion from said claw pull-down.
 5. A combination as defined in claim 4,wherein said driving member is rigid with said claw pull-down.
 6. Acombination as defined in claim 1, wherein said wheel is rigid with saidfilm collecting member.
 7. A combination as defined in claim 1, whereinsaid pawls are disposed substantially diametrically opposite each otherwith reference to the axis of said wheel.
 8. A combination as defined inclaim 7, wherein said carrier is a lever which is pivotable about apredetermined axis and comprises a first arm and a second arm, saidfirst arm receiving motion from said driving member and said pawls beingmounted on said second arm.
 9. A combination as defined in claim 8,wherein the second arm of said lever is substantially U-shaped.
 10. Acombination as defined in claim 1, wherein said motion transmittingmeans further comprises biasing means interposed between said drivingmember and said carrier to normally move said carrier in response tomovement of said driving member.
 11. A combination as defined in claim10, wherein said carrier is a lever which is pivotable in said first andsecond directions about a predetermined axis, said lever having a firstarm which receives motion from said driving member by way of saidbiasing means and a second arm which supports said pawls.
 12. Acombination as defined in claim 11, wherein said second arm of saidlever is substantially U-shaped and said pawls are mounted on saidsecond arm substantially diametrically opposite each other withreference to the axis of said wheel.
 13. A combination as defined inclaim 12, further comprising second biasing means permanently tending topivot said lever in one of said first and second directions.
 14. Acombination as defined in claim 1, wherein said carrier is a leverhaving an arm which supports said pawls, said motion transmitting meansfurther comprising first biasing means engaging said arm and arranged tobias said lever in one of said first and second directions and secondbiasing means arranged to transmit motion from said driving member to aportion of said lever which is remote from the point of engagementbetween said arm and said first biasing means.
 15. A combination asdefined in claim 14, wherein at least one of said biasing means is atorsion spring.